Effect of troponin C on the cooperativity in Ca2+ activation of cardiac muscle

FEBS Letters

Gulati, Jagdish¹  Scordilis, Stylianos¹  Babu, Arvind¹ 

[1]Departments of Medicine and Physiology/Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461 and Smith College, Northampton, MA 01063, USA

关键词: Troponin C;    Structure-function relationship;    Cooperativity;    Regulation;    Amino acid sequence;    Mutagenesis;   

DOI  :  10.1016/0014-5793(88)80073-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This study describes the effects of exchanging native cardiac troponin C (CTnC) from the right ventricular muscle of Syrian hamster for purified skeletal (S) TnC from fast twitch muscles in triggering cardiac contraction. Ca²⁺ sensitivity of the myocardium became decreased with STnC to 62% of the original value with CTnC. Furthermore, the slope of the pCa-force curve of cardiac muscle was found to be increased with STnC. The results show that the TnC moiety, as part of the switching mechanism during activation, also regulates thin-filament cooperativity in muscle. Modifications in both the Ca²⁺ sensitivity and cooperativity are associated with alterations in the primary structure of TnC.

【 授权许可】

Unknown